Two Walkers shows why you keep a sealer; this is the seal you can actually use. Paste any text — a config, a message, a contract, a paragraph — and SEAL it into a SHA-256 receipt. Later, paste the text and the receipt into VERIFY: if a single character changed, the seal breaks. Real, offline, tamper-evident; nothing leaves the page.
IS: a real integrity tool. The receipt is a genuine SHA-256 digest (verified on this bench against the known vector sha256("abc")=ba7816bf…15ad). Any change to the text — one character, one space — produces a different digest, so VERIFY catches tampering with certainty. It runs entirely in your browser; the text never leaves the page. Use it to prove a config, a clause, or a message is byte-for-byte what you sealed.
IS NOT: a signature or a password. SHA-256 proves the text is unchanged, not who wrote it — anyone can reseal altered text with a new receipt, so keep the receipt somewhere the text can't be edited. The little LOCK CHARM (a palindromic-prime grade from the digest) is Walker A's ornament, not the security — the 64-hex receipt is the proof.